1# SPDX-License-Identifier: GPL-2.0-only 2# 3# IP configuration 4# 5config IP_MULTICAST 6 bool "IP: multicasting" 7 help 8 This is code for addressing several networked computers at once, 9 enlarging your kernel by about 2 KB. You need multicasting if you 10 intend to participate in the MBONE, a high bandwidth network on top 11 of the Internet which carries audio and video broadcasts. More 12 information about the MBONE is on the WWW at 13 <http://www.savetz.com/mbone/>. For most people, it's safe to say N. 14 15config IP_ADVANCED_ROUTER 16 bool "IP: advanced router" 17 ---help--- 18 If you intend to run your Linux box mostly as a router, i.e. as a 19 computer that forwards and redistributes network packets, say Y; you 20 will then be presented with several options that allow more precise 21 control about the routing process. 22 23 The answer to this question won't directly affect the kernel: 24 answering N will just cause the configurator to skip all the 25 questions about advanced routing. 26 27 Note that your box can only act as a router if you enable IP 28 forwarding in your kernel; you can do that by saying Y to "/proc 29 file system support" and "Sysctl support" below and executing the 30 line 31 32 echo "1" > /proc/sys/net/ipv4/ip_forward 33 34 at boot time after the /proc file system has been mounted. 35 36 If you turn on IP forwarding, you should consider the rp_filter, which 37 automatically rejects incoming packets if the routing table entry 38 for their source address doesn't match the network interface they're 39 arriving on. This has security advantages because it prevents the 40 so-called IP spoofing, however it can pose problems if you use 41 asymmetric routing (packets from you to a host take a different path 42 than packets from that host to you) or if you operate a non-routing 43 host which has several IP addresses on different interfaces. To turn 44 rp_filter on use: 45 46 echo 1 > /proc/sys/net/ipv4/conf/<device>/rp_filter 47 or 48 echo 1 > /proc/sys/net/ipv4/conf/all/rp_filter 49 50 Note that some distributions enable it in startup scripts. 51 For details about rp_filter strict and loose mode read 52 <file:Documentation/networking/ip-sysctl.txt>. 53 54 If unsure, say N here. 55 56config IP_FIB_TRIE_STATS 57 bool "FIB TRIE statistics" 58 depends on IP_ADVANCED_ROUTER 59 ---help--- 60 Keep track of statistics on structure of FIB TRIE table. 61 Useful for testing and measuring TRIE performance. 62 63config IP_MULTIPLE_TABLES 64 bool "IP: policy routing" 65 depends on IP_ADVANCED_ROUTER 66 select FIB_RULES 67 ---help--- 68 Normally, a router decides what to do with a received packet based 69 solely on the packet's final destination address. If you say Y here, 70 the Linux router will also be able to take the packet's source 71 address into account. Furthermore, the TOS (Type-Of-Service) field 72 of the packet can be used for routing decisions as well. 73 74 If you need more information, see the Linux Advanced 75 Routing and Traffic Control documentation at 76 <http://lartc.org/howto/lartc.rpdb.html> 77 78 If unsure, say N. 79 80config IP_ROUTE_MULTIPATH 81 bool "IP: equal cost multipath" 82 depends on IP_ADVANCED_ROUTER 83 help 84 Normally, the routing tables specify a single action to be taken in 85 a deterministic manner for a given packet. If you say Y here 86 however, it becomes possible to attach several actions to a packet 87 pattern, in effect specifying several alternative paths to travel 88 for those packets. The router considers all these paths to be of 89 equal "cost" and chooses one of them in a non-deterministic fashion 90 if a matching packet arrives. 91 92config IP_ROUTE_VERBOSE 93 bool "IP: verbose route monitoring" 94 depends on IP_ADVANCED_ROUTER 95 help 96 If you say Y here, which is recommended, then the kernel will print 97 verbose messages regarding the routing, for example warnings about 98 received packets which look strange and could be evidence of an 99 attack or a misconfigured system somewhere. The information is 100 handled by the klogd daemon which is responsible for kernel messages 101 ("man klogd"). 102 103config IP_ROUTE_CLASSID 104 bool 105 106config IP_PNP 107 bool "IP: kernel level autoconfiguration" 108 help 109 This enables automatic configuration of IP addresses of devices and 110 of the routing table during kernel boot, based on either information 111 supplied on the kernel command line or by BOOTP or RARP protocols. 112 You need to say Y only for diskless machines requiring network 113 access to boot (in which case you want to say Y to "Root file system 114 on NFS" as well), because all other machines configure the network 115 in their startup scripts. 116 117config IP_PNP_DHCP 118 bool "IP: DHCP support" 119 depends on IP_PNP 120 ---help--- 121 If you want your Linux box to mount its whole root file system (the 122 one containing the directory /) from some other computer over the 123 net via NFS and you want the IP address of your computer to be 124 discovered automatically at boot time using the DHCP protocol (a 125 special protocol designed for doing this job), say Y here. In case 126 the boot ROM of your network card was designed for booting Linux and 127 does DHCP itself, providing all necessary information on the kernel 128 command line, you can say N here. 129 130 If unsure, say Y. Note that if you want to use DHCP, a DHCP server 131 must be operating on your network. Read 132 <file:Documentation/filesystems/nfs/nfsroot.txt> for details. 133 134config IP_PNP_BOOTP 135 bool "IP: BOOTP support" 136 depends on IP_PNP 137 ---help--- 138 If you want your Linux box to mount its whole root file system (the 139 one containing the directory /) from some other computer over the 140 net via NFS and you want the IP address of your computer to be 141 discovered automatically at boot time using the BOOTP protocol (a 142 special protocol designed for doing this job), say Y here. In case 143 the boot ROM of your network card was designed for booting Linux and 144 does BOOTP itself, providing all necessary information on the kernel 145 command line, you can say N here. If unsure, say Y. Note that if you 146 want to use BOOTP, a BOOTP server must be operating on your network. 147 Read <file:Documentation/filesystems/nfs/nfsroot.txt> for details. 148 149config IP_PNP_RARP 150 bool "IP: RARP support" 151 depends on IP_PNP 152 help 153 If you want your Linux box to mount its whole root file system (the 154 one containing the directory /) from some other computer over the 155 net via NFS and you want the IP address of your computer to be 156 discovered automatically at boot time using the RARP protocol (an 157 older protocol which is being obsoleted by BOOTP and DHCP), say Y 158 here. Note that if you want to use RARP, a RARP server must be 159 operating on your network. Read 160 <file:Documentation/filesystems/nfs/nfsroot.txt> for details. 161 162config NET_IPIP 163 tristate "IP: tunneling" 164 select INET_TUNNEL 165 select NET_IP_TUNNEL 166 ---help--- 167 Tunneling means encapsulating data of one protocol type within 168 another protocol and sending it over a channel that understands the 169 encapsulating protocol. This particular tunneling driver implements 170 encapsulation of IP within IP, which sounds kind of pointless, but 171 can be useful if you want to make your (or some other) machine 172 appear on a different network than it physically is, or to use 173 mobile-IP facilities (allowing laptops to seamlessly move between 174 networks without changing their IP addresses). 175 176 Saying Y to this option will produce two modules ( = code which can 177 be inserted in and removed from the running kernel whenever you 178 want). Most people won't need this and can say N. 179 180config NET_IPGRE_DEMUX 181 tristate "IP: GRE demultiplexer" 182 help 183 This is helper module to demultiplex GRE packets on GRE version field criteria. 184 Required by ip_gre and pptp modules. 185 186config NET_IP_TUNNEL 187 tristate 188 select DST_CACHE 189 select GRO_CELLS 190 default n 191 192config NET_IPGRE 193 tristate "IP: GRE tunnels over IP" 194 depends on (IPV6 || IPV6=n) && NET_IPGRE_DEMUX 195 select NET_IP_TUNNEL 196 help 197 Tunneling means encapsulating data of one protocol type within 198 another protocol and sending it over a channel that understands the 199 encapsulating protocol. This particular tunneling driver implements 200 GRE (Generic Routing Encapsulation) and at this time allows 201 encapsulating of IPv4 or IPv6 over existing IPv4 infrastructure. 202 This driver is useful if the other endpoint is a Cisco router: Cisco 203 likes GRE much better than the other Linux tunneling driver ("IP 204 tunneling" above). In addition, GRE allows multicast redistribution 205 through the tunnel. 206 207config NET_IPGRE_BROADCAST 208 bool "IP: broadcast GRE over IP" 209 depends on IP_MULTICAST && NET_IPGRE 210 help 211 One application of GRE/IP is to construct a broadcast WAN (Wide Area 212 Network), which looks like a normal Ethernet LAN (Local Area 213 Network), but can be distributed all over the Internet. If you want 214 to do that, say Y here and to "IP multicast routing" below. 215 216config IP_MROUTE_COMMON 217 bool 218 depends on IP_MROUTE || IPV6_MROUTE 219 220config IP_MROUTE 221 bool "IP: multicast routing" 222 depends on IP_MULTICAST 223 select IP_MROUTE_COMMON 224 help 225 This is used if you want your machine to act as a router for IP 226 packets that have several destination addresses. It is needed on the 227 MBONE, a high bandwidth network on top of the Internet which carries 228 audio and video broadcasts. In order to do that, you would most 229 likely run the program mrouted. If you haven't heard about it, you 230 don't need it. 231 232config IP_MROUTE_MULTIPLE_TABLES 233 bool "IP: multicast policy routing" 234 depends on IP_MROUTE && IP_ADVANCED_ROUTER 235 select FIB_RULES 236 help 237 Normally, a multicast router runs a userspace daemon and decides 238 what to do with a multicast packet based on the source and 239 destination addresses. If you say Y here, the multicast router 240 will also be able to take interfaces and packet marks into 241 account and run multiple instances of userspace daemons 242 simultaneously, each one handling a single table. 243 244 If unsure, say N. 245 246config IP_PIMSM_V1 247 bool "IP: PIM-SM version 1 support" 248 depends on IP_MROUTE 249 help 250 Kernel side support for Sparse Mode PIM (Protocol Independent 251 Multicast) version 1. This multicast routing protocol is used widely 252 because Cisco supports it. You need special software to use it 253 (pimd-v1). Please see <http://netweb.usc.edu/pim/> for more 254 information about PIM. 255 256 Say Y if you want to use PIM-SM v1. Note that you can say N here if 257 you just want to use Dense Mode PIM. 258 259config IP_PIMSM_V2 260 bool "IP: PIM-SM version 2 support" 261 depends on IP_MROUTE 262 help 263 Kernel side support for Sparse Mode PIM version 2. In order to use 264 this, you need an experimental routing daemon supporting it (pimd or 265 gated-5). This routing protocol is not used widely, so say N unless 266 you want to play with it. 267 268config SYN_COOKIES 269 bool "IP: TCP syncookie support" 270 ---help--- 271 Normal TCP/IP networking is open to an attack known as "SYN 272 flooding". This denial-of-service attack prevents legitimate remote 273 users from being able to connect to your computer during an ongoing 274 attack and requires very little work from the attacker, who can 275 operate from anywhere on the Internet. 276 277 SYN cookies provide protection against this type of attack. If you 278 say Y here, the TCP/IP stack will use a cryptographic challenge 279 protocol known as "SYN cookies" to enable legitimate users to 280 continue to connect, even when your machine is under attack. There 281 is no need for the legitimate users to change their TCP/IP software; 282 SYN cookies work transparently to them. For technical information 283 about SYN cookies, check out <http://cr.yp.to/syncookies.html>. 284 285 If you are SYN flooded, the source address reported by the kernel is 286 likely to have been forged by the attacker; it is only reported as 287 an aid in tracing the packets to their actual source and should not 288 be taken as absolute truth. 289 290 SYN cookies may prevent correct error reporting on clients when the 291 server is really overloaded. If this happens frequently better turn 292 them off. 293 294 If you say Y here, you can disable SYN cookies at run time by 295 saying Y to "/proc file system support" and 296 "Sysctl support" below and executing the command 297 298 echo 0 > /proc/sys/net/ipv4/tcp_syncookies 299 300 after the /proc file system has been mounted. 301 302 If unsure, say N. 303 304config NET_IPVTI 305 tristate "Virtual (secure) IP: tunneling" 306 select INET_TUNNEL 307 select NET_IP_TUNNEL 308 select XFRM 309 ---help--- 310 Tunneling means encapsulating data of one protocol type within 311 another protocol and sending it over a channel that understands the 312 encapsulating protocol. This can be used with xfrm mode tunnel to give 313 the notion of a secure tunnel for IPSEC and then use routing protocol 314 on top. 315 316config NET_UDP_TUNNEL 317 tristate 318 select NET_IP_TUNNEL 319 default n 320 321config NET_FOU 322 tristate "IP: Foo (IP protocols) over UDP" 323 select XFRM 324 select NET_UDP_TUNNEL 325 ---help--- 326 Foo over UDP allows any IP protocol to be directly encapsulated 327 over UDP include tunnels (IPIP, GRE, SIT). By encapsulating in UDP 328 network mechanisms and optimizations for UDP (such as ECMP 329 and RSS) can be leveraged to provide better service. 330 331config NET_FOU_IP_TUNNELS 332 bool "IP: FOU encapsulation of IP tunnels" 333 depends on NET_IPIP || NET_IPGRE || IPV6_SIT 334 select NET_FOU 335 ---help--- 336 Allow configuration of FOU or GUE encapsulation for IP tunnels. 337 When this option is enabled IP tunnels can be configured to use 338 FOU or GUE encapsulation. 339 340config INET_AH 341 tristate "IP: AH transformation" 342 select XFRM_ALGO 343 select CRYPTO 344 select CRYPTO_HMAC 345 select CRYPTO_MD5 346 select CRYPTO_SHA1 347 ---help--- 348 Support for IPsec AH. 349 350 If unsure, say Y. 351 352config INET_ESP 353 tristate "IP: ESP transformation" 354 select XFRM_ALGO 355 select CRYPTO 356 select CRYPTO_AUTHENC 357 select CRYPTO_HMAC 358 select CRYPTO_MD5 359 select CRYPTO_CBC 360 select CRYPTO_SHA1 361 select CRYPTO_DES 362 select CRYPTO_ECHAINIV 363 ---help--- 364 Support for IPsec ESP. 365 366 If unsure, say Y. 367 368config INET_ESP_OFFLOAD 369 tristate "IP: ESP transformation offload" 370 depends on INET_ESP 371 select XFRM_OFFLOAD 372 default n 373 ---help--- 374 Support for ESP transformation offload. This makes sense 375 only if this system really does IPsec and want to do it 376 with high throughput. A typical desktop system does not 377 need it, even if it does IPsec. 378 379 If unsure, say N. 380 381config INET_IPCOMP 382 tristate "IP: IPComp transformation" 383 select INET_XFRM_TUNNEL 384 select XFRM_IPCOMP 385 ---help--- 386 Support for IP Payload Compression Protocol (IPComp) (RFC3173), 387 typically needed for IPsec. 388 389 If unsure, say Y. 390 391config INET_XFRM_TUNNEL 392 tristate 393 select INET_TUNNEL 394 default n 395 396config INET_TUNNEL 397 tristate 398 default n 399 400config INET_DIAG 401 tristate "INET: socket monitoring interface" 402 default y 403 ---help--- 404 Support for INET (TCP, DCCP, etc) socket monitoring interface used by 405 native Linux tools such as ss. ss is included in iproute2, currently 406 downloadable at: 407 408 http://www.linuxfoundation.org/collaborate/workgroups/networking/iproute2 409 410 If unsure, say Y. 411 412config INET_TCP_DIAG 413 depends on INET_DIAG 414 def_tristate INET_DIAG 415 416config INET_UDP_DIAG 417 tristate "UDP: socket monitoring interface" 418 depends on INET_DIAG && (IPV6 || IPV6=n) 419 default n 420 ---help--- 421 Support for UDP socket monitoring interface used by the ss tool. 422 If unsure, say Y. 423 424config INET_RAW_DIAG 425 tristate "RAW: socket monitoring interface" 426 depends on INET_DIAG && (IPV6 || IPV6=n) 427 default n 428 ---help--- 429 Support for RAW socket monitoring interface used by the ss tool. 430 If unsure, say Y. 431 432config INET_DIAG_DESTROY 433 bool "INET: allow privileged process to administratively close sockets" 434 depends on INET_DIAG 435 default n 436 ---help--- 437 Provides a SOCK_DESTROY operation that allows privileged processes 438 (e.g., a connection manager or a network administration tool such as 439 ss) to close sockets opened by other processes. Closing a socket in 440 this way interrupts any blocking read/write/connect operations on 441 the socket and causes future socket calls to behave as if the socket 442 had been disconnected. 443 If unsure, say N. 444 445menuconfig TCP_CONG_ADVANCED 446 bool "TCP: advanced congestion control" 447 ---help--- 448 Support for selection of various TCP congestion control 449 modules. 450 451 Nearly all users can safely say no here, and a safe default 452 selection will be made (CUBIC with new Reno as a fallback). 453 454 If unsure, say N. 455 456if TCP_CONG_ADVANCED 457 458config TCP_CONG_BIC 459 tristate "Binary Increase Congestion (BIC) control" 460 default m 461 ---help--- 462 BIC-TCP is a sender-side only change that ensures a linear RTT 463 fairness under large windows while offering both scalability and 464 bounded TCP-friendliness. The protocol combines two schemes 465 called additive increase and binary search increase. When the 466 congestion window is large, additive increase with a large 467 increment ensures linear RTT fairness as well as good 468 scalability. Under small congestion windows, binary search 469 increase provides TCP friendliness. 470 See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/ 471 472config TCP_CONG_CUBIC 473 tristate "CUBIC TCP" 474 default y 475 ---help--- 476 This is version 2.0 of BIC-TCP which uses a cubic growth function 477 among other techniques. 478 See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/cubic-paper.pdf 479 480config TCP_CONG_WESTWOOD 481 tristate "TCP Westwood+" 482 default m 483 ---help--- 484 TCP Westwood+ is a sender-side only modification of the TCP Reno 485 protocol stack that optimizes the performance of TCP congestion 486 control. It is based on end-to-end bandwidth estimation to set 487 congestion window and slow start threshold after a congestion 488 episode. Using this estimation, TCP Westwood+ adaptively sets a 489 slow start threshold and a congestion window which takes into 490 account the bandwidth used at the time congestion is experienced. 491 TCP Westwood+ significantly increases fairness wrt TCP Reno in 492 wired networks and throughput over wireless links. 493 494config TCP_CONG_HTCP 495 tristate "H-TCP" 496 default m 497 ---help--- 498 H-TCP is a send-side only modifications of the TCP Reno 499 protocol stack that optimizes the performance of TCP 500 congestion control for high speed network links. It uses a 501 modeswitch to change the alpha and beta parameters of TCP Reno 502 based on network conditions and in a way so as to be fair with 503 other Reno and H-TCP flows. 504 505config TCP_CONG_HSTCP 506 tristate "High Speed TCP" 507 default n 508 ---help--- 509 Sally Floyd's High Speed TCP (RFC 3649) congestion control. 510 A modification to TCP's congestion control mechanism for use 511 with large congestion windows. A table indicates how much to 512 increase the congestion window by when an ACK is received. 513 For more detail see http://www.icir.org/floyd/hstcp.html 514 515config TCP_CONG_HYBLA 516 tristate "TCP-Hybla congestion control algorithm" 517 default n 518 ---help--- 519 TCP-Hybla is a sender-side only change that eliminates penalization of 520 long-RTT, large-bandwidth connections, like when satellite legs are 521 involved, especially when sharing a common bottleneck with normal 522 terrestrial connections. 523 524config TCP_CONG_VEGAS 525 tristate "TCP Vegas" 526 default n 527 ---help--- 528 TCP Vegas is a sender-side only change to TCP that anticipates 529 the onset of congestion by estimating the bandwidth. TCP Vegas 530 adjusts the sending rate by modifying the congestion 531 window. TCP Vegas should provide less packet loss, but it is 532 not as aggressive as TCP Reno. 533 534config TCP_CONG_NV 535 tristate "TCP NV" 536 default n 537 ---help--- 538 TCP NV is a follow up to TCP Vegas. It has been modified to deal with 539 10G networks, measurement noise introduced by LRO, GRO and interrupt 540 coalescence. In addition, it will decrease its cwnd multiplicatively 541 instead of linearly. 542 543 Note that in general congestion avoidance (cwnd decreased when # packets 544 queued grows) cannot coexist with congestion control (cwnd decreased only 545 when there is packet loss) due to fairness issues. One scenario when they 546 can coexist safely is when the CA flows have RTTs << CC flows RTTs. 547 548 For further details see http://www.brakmo.org/networking/tcp-nv/ 549 550config TCP_CONG_SCALABLE 551 tristate "Scalable TCP" 552 default n 553 ---help--- 554 Scalable TCP is a sender-side only change to TCP which uses a 555 MIMD congestion control algorithm which has some nice scaling 556 properties, though is known to have fairness issues. 557 See http://www.deneholme.net/tom/scalable/ 558 559config TCP_CONG_LP 560 tristate "TCP Low Priority" 561 default n 562 ---help--- 563 TCP Low Priority (TCP-LP), a distributed algorithm whose goal is 564 to utilize only the excess network bandwidth as compared to the 565 ``fair share`` of bandwidth as targeted by TCP. 566 See http://www-ece.rice.edu/networks/TCP-LP/ 567 568config TCP_CONG_VENO 569 tristate "TCP Veno" 570 default n 571 ---help--- 572 TCP Veno is a sender-side only enhancement of TCP to obtain better 573 throughput over wireless networks. TCP Veno makes use of state 574 distinguishing to circumvent the difficult judgment of the packet loss 575 type. TCP Veno cuts down less congestion window in response to random 576 loss packets. 577 See <http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=1177186> 578 579config TCP_CONG_YEAH 580 tristate "YeAH TCP" 581 select TCP_CONG_VEGAS 582 default n 583 ---help--- 584 YeAH-TCP is a sender-side high-speed enabled TCP congestion control 585 algorithm, which uses a mixed loss/delay approach to compute the 586 congestion window. It's design goals target high efficiency, 587 internal, RTT and Reno fairness, resilience to link loss while 588 keeping network elements load as low as possible. 589 590 For further details look here: 591 http://wil.cs.caltech.edu/pfldnet2007/paper/YeAH_TCP.pdf 592 593config TCP_CONG_ILLINOIS 594 tristate "TCP Illinois" 595 default n 596 ---help--- 597 TCP-Illinois is a sender-side modification of TCP Reno for 598 high speed long delay links. It uses round-trip-time to 599 adjust the alpha and beta parameters to achieve a higher average 600 throughput and maintain fairness. 601 602 For further details see: 603 http://www.ews.uiuc.edu/~shaoliu/tcpillinois/index.html 604 605config TCP_CONG_DCTCP 606 tristate "DataCenter TCP (DCTCP)" 607 default n 608 ---help--- 609 DCTCP leverages Explicit Congestion Notification (ECN) in the network to 610 provide multi-bit feedback to the end hosts. It is designed to provide: 611 612 - High burst tolerance (incast due to partition/aggregate), 613 - Low latency (short flows, queries), 614 - High throughput (continuous data updates, large file transfers) with 615 commodity, shallow-buffered switches. 616 617 All switches in the data center network running DCTCP must support 618 ECN marking and be configured for marking when reaching defined switch 619 buffer thresholds. The default ECN marking threshold heuristic for 620 DCTCP on switches is 20 packets (30KB) at 1Gbps, and 65 packets 621 (~100KB) at 10Gbps, but might need further careful tweaking. 622 623 For further details see: 624 http://simula.stanford.edu/~alizade/Site/DCTCP_files/dctcp-final.pdf 625 626config TCP_CONG_CDG 627 tristate "CAIA Delay-Gradient (CDG)" 628 default n 629 ---help--- 630 CAIA Delay-Gradient (CDG) is a TCP congestion control that modifies 631 the TCP sender in order to: 632 633 o Use the delay gradient as a congestion signal. 634 o Back off with an average probability that is independent of the RTT. 635 o Coexist with flows that use loss-based congestion control. 636 o Tolerate packet loss unrelated to congestion. 637 638 For further details see: 639 D.A. Hayes and G. Armitage. "Revisiting TCP congestion control using 640 delay gradients." In Networking 2011. Preprint: http://goo.gl/No3vdg 641 642config TCP_CONG_BBR 643 tristate "BBR TCP" 644 default n 645 ---help--- 646 647 BBR (Bottleneck Bandwidth and RTT) TCP congestion control aims to 648 maximize network utilization and minimize queues. It builds an explicit 649 model of the the bottleneck delivery rate and path round-trip 650 propagation delay. It tolerates packet loss and delay unrelated to 651 congestion. It can operate over LAN, WAN, cellular, wifi, or cable 652 modem links. It can coexist with flows that use loss-based congestion 653 control, and can operate with shallow buffers, deep buffers, 654 bufferbloat, policers, or AQM schemes that do not provide a delay 655 signal. It requires the fq ("Fair Queue") pacing packet scheduler. 656 657choice 658 prompt "Default TCP congestion control" 659 default DEFAULT_CUBIC 660 help 661 Select the TCP congestion control that will be used by default 662 for all connections. 663 664 config DEFAULT_BIC 665 bool "Bic" if TCP_CONG_BIC=y 666 667 config DEFAULT_CUBIC 668 bool "Cubic" if TCP_CONG_CUBIC=y 669 670 config DEFAULT_HTCP 671 bool "Htcp" if TCP_CONG_HTCP=y 672 673 config DEFAULT_HYBLA 674 bool "Hybla" if TCP_CONG_HYBLA=y 675 676 config DEFAULT_VEGAS 677 bool "Vegas" if TCP_CONG_VEGAS=y 678 679 config DEFAULT_VENO 680 bool "Veno" if TCP_CONG_VENO=y 681 682 config DEFAULT_WESTWOOD 683 bool "Westwood" if TCP_CONG_WESTWOOD=y 684 685 config DEFAULT_DCTCP 686 bool "DCTCP" if TCP_CONG_DCTCP=y 687 688 config DEFAULT_CDG 689 bool "CDG" if TCP_CONG_CDG=y 690 691 config DEFAULT_BBR 692 bool "BBR" if TCP_CONG_BBR=y 693 694 config DEFAULT_RENO 695 bool "Reno" 696endchoice 697 698endif 699 700config TCP_CONG_CUBIC 701 tristate 702 depends on !TCP_CONG_ADVANCED 703 default y 704 705config DEFAULT_TCP_CONG 706 string 707 default "bic" if DEFAULT_BIC 708 default "cubic" if DEFAULT_CUBIC 709 default "htcp" if DEFAULT_HTCP 710 default "hybla" if DEFAULT_HYBLA 711 default "vegas" if DEFAULT_VEGAS 712 default "westwood" if DEFAULT_WESTWOOD 713 default "veno" if DEFAULT_VENO 714 default "reno" if DEFAULT_RENO 715 default "dctcp" if DEFAULT_DCTCP 716 default "cdg" if DEFAULT_CDG 717 default "bbr" if DEFAULT_BBR 718 default "cubic" 719 720config TCP_MD5SIG 721 bool "TCP: MD5 Signature Option support (RFC2385)" 722 select CRYPTO 723 select CRYPTO_MD5 724 ---help--- 725 RFC2385 specifies a method of giving MD5 protection to TCP sessions. 726 Its main (only?) use is to protect BGP sessions between core routers 727 on the Internet. 728 729 If unsure, say N. 730